Malicious PDF — malware analysis report

Static analysis result for SHA-256 855d9d90444307c3…

MALICIOUS

PDF

43.4 KB Created: 2020-03-12 11:19:07 +02:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-09-24
MD5: e0084c8c98708de43260f5bee77eeab3 SHA-1: 0da9aad0baadb54a2c66f9ed3b595096a9810579 SHA-256: 855d9d90444307c3310771195689712e43ebd0a4af5da23a7a35d20f7c7eca2b
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file contains a large number of external links, many of which point to other PDF files with numeric slugs, indicating a potential link farm or SEO spam operation. The ML classifier strongly flagged this sample as malicious. While no scripts were explicitly extracted, the PDF structure and numerous external URLs suggest an attempt to redirect users to potentially malicious content or further stages of an attack.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://host45.carmichaelnl.com/uploads/1/3/0/2/130287873/130287873.html#three+methods+of+solving+simultaneous+equations+pdf PDF link annotation
    • http://afagamentoenvernizamentoparquet.com/uploads/1/3/0/4/130489377/52871.pdfIn PDF document text
    • http://caseybradleyarts.com/uploads/1/3/0/8/130814475/c16b35af9.pdfIn PDF document text
    • http://wdavidpower.com/uploads/1/3/0/2/130272610/watuxegenusinalaf.pdfIn PDF document text
    • http://ashleystouch.org/uploads/1/3/0/7/130775033/3969527.pdfIn PDF document text
    • http://turbo23.es/uploads/1/3/0/5/130590217/4890031.pdfIn PDF document text
    • http://www.zhiyouexpressinc.com/uploads/1/3/0/7/130776103/1146799.pdfIn PDF document text
    • http://pgcinternational.net/uploads/1/3/0/4/130476440/lixipog-popob-xigumaz.pdfIn PDF document text
    • http://gauravs.in/uploads/1/3/0/5/130541803/5655802.pdfIn PDF document text
    • http://omnicamlab.com/uploads/1/3/0/5/130589194/2434154.pdfIn PDF document text
    • http://www.vmcontractingservices.com/uploads/1/3/0/6/130620428/7829195.pdfIn PDF document text
    • http://www.terrimiles.co.uk/uploads/1/3/0/2/130272336/vogeb-tivakofeg.pdfIn PDF document text
    • http://tannerromleski.com/uploads/1/3/0/6/130639155/518c97c03b.pdfIn PDF document text
    • http://scotlandcp.com/uploads/1/3/0/5/130544584/2964176.pdfIn PDF document text
    • http://eddie-ieong.com/uploads/1/3/0/5/130588417/raxus.pdfIn PDF document text
    • http://openmindsholistichealingcenter.com/uploads/1/3/0/4/130435857/7671344.pdfIn PDF document text
    • http://thechristinaleavenworth.com/uploads/1/3/0/4/130435670/ziwekiroko.pdfIn PDF document text
    • http://i2ionline.com/uploads/1/3/0/2/130272403/vugomuwejexi.pdfIn PDF document text
    • http://thenashvillebite.com/uploads/1/3/0/7/130775503/benawidutoxiril-derokon.pdfIn PDF document text
    • http://livingmydogsbestlife.com/uploads/1/3/0/5/130588352/zotiwot-wovonilategeje.pdfIn PDF document text
    • http://dazhongyulechengdailizhuce.f18.ebkf.org/uploads/1/3/0/6/130604196/c4e09eb19.pdfIn PDF document text
    • http://www.sundaybrunchkitchen.co.nz/uploads/1/3/0/3/130323630/tifilabepiwezos_juzudiluliwuk.pdfIn PDF document text
    • http://staging2.highschoolspanish.org/uploads/1/3/0/9/130969614/bc2772c4679129.pdfIn PDF document text
    • http://uec.la/uploads/1/3/0/5/130550703/piwuj-bixereji-zoniwedu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • https://fedoraproject.org/wiki/Licensing/LiberationFontLicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007464.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7464 8688 bytes
SHA-256: 5b949a6de4b2cc0a335632ba7b346031c971ebf485a8b9fbbe64132b79a67516
font_01_sfnt_off000095dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x95DD 2652 bytes
SHA-256: 3d52fc27d04b8b84b219df719738f768697e09c2050136bc1fe69fcddf4eca6e